#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;
double a[105];
bool cmp(double b,double c){
    return b>c;
}
int main(void){
    int t;
    scanf("%d",&t);
    while(t--){
        int n;
        scanf("%d",&n);
        for(int i=0;i<n;i++){
            scanf("%lf",&a[i]);
        }
        sort(a,a+n,cmp);
        printf("%lf\n",a[0]);
    }
    return 0;
}
